In this section of the tutorial we will build a model of a typical ophthalmology unit. Patients arrive to the department to undergo the ophthalmoscopy procedure. They are held in the waiting room and wait for ophthalmologists to come and make an examination. The procedure is held in the procedure room. When a doctor arrives, patient moves to empty procedure room escorted by the doctor. The procedure is performed using an ophthalmoscope. Ophthalmoscopes are stored in the storage room and are taken by doctors just before the procedure begins. Following the procedure, the doctor transports the ophthalmoscope back to the storage room and returns to the staffroom, and the patient leaves the ophthalmology department.

We will construct our model using network based modeling blocks. A group of the Enterprise Library objects with common prefix "Network" enable network- or layout-based modeling. Typically, they are used when the processes being modeled are going on in a certain physical space and include movement of entities and resources. Entities can move along paths of the network and use resources located in that network.